European Mars Lander Crashed Due to Data Glitch, ESA Concludes

Zoomed-in view of the crater gouged out by Europe's Schiaparelli Mars lander when it crashed on Oct. 19, 2016. NASA's Mars Reconnaissance Orbiter took the photo on Nov. 1, 2016.

Credit: NASA/JPL-Caltech/Univ. of Arizona

The reason Europe's Schiaparelli Mars lander failed to touch down safely last fall is that conflicting data confused the craft's onboard computer, according to the newly completed crash investigation.

Things started to go wrong for Schiaparelli about 3 minutes after it hit the Martian atmosphere on Oct. 19, 2016. At that time, the lander deployed its parachute and then began spinning unexpectedly fast, according to the investigation, which concluded last week.

"The incorrect attitude estimate, when combined with the later radar measurements, resulted in the computer calculating that it was below ground level," the officials added. "This resulted in the early release of the parachute and backshell, a brief firing of the thrusters for only 3 seconds instead of 30 seconds, and the activation of the on-ground system as if Schiaparelli had landed."

In reality, however, the lander was still about 2.3 miles (3.7 kilometers) up in the Martian sky, and falling fast. It ended up slamming into the red dirt at an estimated 335 mph (540 km/h), ESA officials said. The high-energy impact destroyed Schiaparelli and left a black scar that NASA's Mars Reconnaissance Orbiter was able to spot from space.

How the touchdown of ExoMars' Schiaparelli lander was supposed to happen on Oct. 19, 2016.

Schiaparelli launched in March 2016 along with the Trace Gas Orbiter (TGO). Together, the two craft made up the first part of the two-phase ExoMars program, a project led by ESA with Russia's federal space agency, Roscosmos, as the main partner.

TGO made it to orbit as planned in October 2016 and is now working its way toward its desired science orbit. When TGO gets there in early 2018, the orbiter will begin searching the Martian atmosphere for methane and other gases that could be signs of Red Planet life.

ExoMars' second phase centers on a life-hunting rover that's scheduled to launch in 2020. While Schiaparelli was equipped with a few science instruments, the lander's main job was to prove out the technology required to land the ExoMars rover safely.

These photos, taken by NASA's Mars Reconnaissance Orbiter on Nov. 1, 2016, show the wreckage of Europe's Schiaparelli lander. Top: the crater caused by the lander's impact. Bottom left: the craft's parachute and attached back heat shield. Bottom right: a feature thought to be the front heat shield. The 10-meter scale bar applies to all three portions of the image.

Credit: NASA/JPL-Caltech/Univ. of Arizona

That obviously didn't happen, but the crash and subsequent investigation have provided a great deal of useful information, ESA officials said.

"Interestingly, had the saturation not occurred and [had] the final stages of landing … been successful, we probably would not have identified the other weak spots that contributed to the mishap," ESA Director General Jan Woerner said in the ESA statement. "As a direct result of this inquiry, we have discovered the areas that require particular attention that will benefit the 2020 mission."

Such "weak spots" include computer models of parachute behavior and software that needs to be upgraded, ESA officials said.

Michael was a science writer for the Idaho National Laboratory and has been an intern at Wired.com, The Salinas Californian newspaper, and the SLAC National Accelerator Laboratory. He has also worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Mike on Google+.